#include <iostream>
#include <vector>
#include <tuple>
#include <queue>
#include <stack>
#include <deque>
#include <set>
#include <map>
#include <cmath>
#include <array>
#include <random>
#include <string>
#include <cassert>
#include <climits>
#include <algorithm>
#include <unordered_set>
#include <unordered_map>
using namespace std;
#define ll long long
#define f first
#define s second
void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\'' << x << '\''; }
void __print(const char *x) { cerr << '\"' << x << '\"'; }
void __print(const string &x) { cerr << '\"' << x << '\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }
template<typename A> void __print(const A &x);
template<typename A, typename B> void __print(const pair<A, B> &p);
template<typename... A> void __print(const tuple<A...> &t);
template<typename T> void __print(stack<T> s);
template<typename T> void __print(queue<T> q);
template<typename T, typename... U> void __print(priority_queue<T, U...> q);
template<typename A> void __print(const A &x) {
bool first = true;
cerr << '{';
for (const auto &i : x) {
cerr << (first ? "" : ","), __print(i);
first = false;
}
cerr << '}';
}
template<typename A, typename B> void __print(const pair<A, B> &p) {
cerr << '(';
__print(p.f);
cerr << ',';
__print(p.s);
cerr << ')';
}
template<typename... A> void __print(const tuple<A...> &t) {
bool first = true;
cerr << '(';
apply([&first] (const auto &...args) { ((cerr << (first ? "" : ","), __print(args), first = false), ...); }, t);
cerr << ')';
}
template<typename T> void __print(stack<T> s) {
vector<T> debugVector;
while (!s.empty()) {
T t = s.top();
debugVector.push_back(t);
s.pop();
}
reverse(debugVector.begin(), debugVector.end());
__print(debugVector);
}
template<typename T> void __print(queue<T> q) {
vector<T> debugVector;
while (!q.empty()) {
T t = q.front();
debugVector.push_back(t);
q.pop();
}
__print(debugVector);
}
template<typename T, typename... U> void __print(priority_queue<T, U...> q) {
vector<T> debugVector;
while (!q.empty()) {
T t = q.top();
debugVector.push_back(t);
q.pop();
}
__print(debugVector);
}
void _print() { cerr << "]\n"; }
template <typename Head, typename... Tail> void _print(const Head &H, const Tail &...T) {
__print(H);
if (sizeof...(T)) cerr << ", ";
_print(T...);
}
#ifdef DEBUG
#define D(...) cerr << "Line: " << __LINE__ << " [" << #__VA_ARGS__ << "] = ["; _print(__VA_ARGS__)
#else
#define D(...)
#endif
int n, p, q, l, r, dp[2005][2005];
vector<pair<int, int>> events;
bool valid(int x) {
fill(&dp[0][0], &dp[0][0] + sizeof(dp) / sizeof(dp[0][0]), 0);
for (int i = 1, idx1, idx2; i <= n; i++) {
idx1 = lower_bound(events.begin(), events.end(), make_pair(events[i].f - x, 0)) - events.begin() - 1;
idx2 = lower_bound(events.begin(), events.end(), make_pair(events[i].f - 2 * x, 0)) - events.begin() - 1;
for (int j = 0; j <= q; j++) {
dp[i][j] = dp[idx1][j] + 1;
if (j) {
dp[i][j] = min(dp[i][j], dp[idx2][j - 1]);
}
}
}
return dp[n][q] <= p;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cin >> n >> p >> q;
events.push_back({-2e9 - 100, -2e9 - 100});
for (int i = 1, x; i <= n; i++) {
cin >> x;
events.push_back({x, i});
}
sort(events.begin(), events.end());
if (p + q >= n) {
cout << 1 << "\n";
exit(0);
}
l = 0, r = 1e9;
while (l + 1 != r) {
int m = (l + r) / 2;
if (valid(m)) r = m;
else l = m;
}
cout << r + 1 << "\n";
}
